Red iron oxide

Red iron oxide is a mineral pigment of natural or synthetic origin, used since antiquity for its colouring properties. Its characteristic hue, ranging from brick red to reddish-brown, results from the presence of oxidised iron in the form of haematite (Fe₂O₃). In the food supplement industry, it is used as a colourant (E172) to tint capsules, coatings and tablets. Red iron oxide is considered chemically inert at the doses used in formulation: it has no intrinsic pharmacological activity and is not significantly absorbed by the body. Its role is purely functional, allowing products to be visually identified and distinguished from one another. Its use is governed by European regulations, which set maximum permitted levels to ensure the safety of the colourant. It is therefore a common excipient in the food supplement industry, chosen for its stability, light resistance and good compatibility with most solid matrices.